This study will assess the motor parameters of the small and large intestine in the diarrheal state. Laxatives will be used to induce diarrhea. The classical concept associates diarrhea with an increase in motor activity. Various clinical conditions e.g., ulcerative colitis have been found to be associated with colonic hypomotility. We propose to objectively assess the motor parameters occuring during laxative induced diarrhea. The technique employed to monitor smooth muscle activity will involve the recently developed extraluminal force transducer. This method permits the use of unanesthetized healthy dogs in which all reflexes are viable. Objective information on the state of the smooth muscle of the intestine during diarrhea would lead to a better understanding and possibly a more rational approach for treatment of patients with diarrheal conditions.